The present invention relates to regions of interest in medical imaging. In particular, regions of interest are identified and/or used for generating displays.
Regions of interest are used for various purposes in medical imaging. For example, a region of interest is used in ultrasound imaging for quantifying contrast agent studies. A region of interest is selected in the image. An intensity associated with the region is displayed as a function of time, providing a time-intensity curve. Where multiple regions of interest are identified in an image, separate time-intensity curves are provided.
As an alternative to selecting regions of interest, parametric images are generated. For example, a value is calculated for each pixel based on medical image information. For contrast studies, the value may be associated with an intensity at a given time. Strain, strain rate or other parametric imaging may be provided. Since each pixel is represented in a parametric image, improved spatial resolution is provided. However, a single parametric image may provide little or no information showing a characteristic or value as a function of time. Parametric images may also lack regional based information.
Identifying a region of interest within a medical image may be laborious. Identifying a plurality of regions of interest within an image may be even more laborious. For example, the user traces each region of interest using a user input. Some semi-automated processes may be used for decreasing an amount of time used to designate regions of interest. For example, the user selects a plurality of nodes of points within an image, and a processor uses the nodes to define a region of interest along a border or boundary that passes through the nodes. Edge detection algorithms may be used in a completely automated process. For example, a boundary between the myocardium and a cardiac chamber or the outer edge (i.e. epicardium) is detected. However, automated processes may be inexact. It is important that the regions of interest do not inadvertently include the ventricle in cardiac contrast agent studies to avoid incorrect calculations of perfusion of muscle tissue or the myocardium.